Electrolytic plating apparatus



Nov. 1955 P. A. BURGEMEISTER ETAL 2,723,953

ELECTROLYTIC PLATING APPARATUS 3 Sheets-Sheet 1 Filed Nov. 9, 1951 Emi I mu l l I I' INVENTOR ATTORNEYS NOV. 1955 P. ABURGEMEISTER ETAL 2,723,953

ELECTROLYTIC PLATING APPARATUS 5 Sheets-Sheet 2 Filed Nov. 9, 1951 INVENTOR HAUL A. BURGEMEISTER THOMAS J. HEALY BYMM w, ZW

ATTORNEYS N v- 1955 P. A. BURGEMEISTER ET AL 2,723,953

ELECTROLYTIC PLATING APPARATUS 5 Sheets-Sheet 3 Filed Nov. 9, 1951 INVENTOR PAUL A. BURGEMEISTER THOMAS J HEALY ATTORNEYS United States Patent ELECTROLYTIC PLATIN G APPARATUS Paul A. Burgemeister, Baltimore, and Thomas J. Healy,

Parkville, Md., assignors to Crown Cork 8; Seal Cornpany, Inc., Baltimore, Md., a corporation of New York Application November 9, 1951, Serial No. 255,654

Claims. (Cl. 204-211 This invention relates to electrolytic plating and particularly to apparatus for electrolytic plating in which differing weights of material may be deposited upon the respective sides of an elongated strip according to a desired ratio. 7

The invention particularly relates to electrolytic plating in which an elongated strip of material to be plated is moved through a plating tank in and about which are positioned rollers for guiding the strip successively past a plurality of plating anodes. The anodes are customarily positioned either in one tank or in plurality of tanks so that certain of the anodes plate on one side of the strip and other anodes plate on the opposite side of the strip.

In the past, it has been customary to have an equal number of anodes positioned to plate on both sides of the strip and furthermore the anodes have been supplied with equal current distribution. The result of that practice has been that strips are plated on both sides with an equal deposit of material, whether an equal deposit on both sides is required or not.

In an effort to conserve plating metal, particularly tin, it has been found that in many uses of tinplate, a considerably reduced weight of tin on one side of the base metal can be tolerated. f Accordingly,,the present invention has been developed to provide a ready means for so plating the opposite sides of the base metal according to a predetermined ratio of deposit weights. It is conceivably possible to carry out ratio plating by completely removing certain anodes from the plating tank or to permanently disconnect such anodes. However, it is usually a difficult and time-consuming task to completely detach and remove an anode, and as for permanently disconnecting an anode, the anode will corrode by building up a film thereover which eventually will render the anode unusable.

According to the present invention an arrangement is provided in which predetermined anodes plating on the respective sides of the base metal may be disconnected for given intervals of time. With a suflicient number of anodes provided so that they may be divided into groups, first one group and then another can be selectively disconnected to provide a reduced deposit of plating metal and yet at the same time particular anodes can be reactivated and others disconnected over suitable time periods so that none of the anodes is destroyed by being idle too long.

It is therefore a primary object of this invention to provide plating apparatus in which ratio plating may be accomplished by selectively disconnecting one or more anodes in sequence.

Further objects and the entire scope of the invention will become more apparent from the following detailed description and from the appended claims.

The invention may be best understood with reference to the accompanying drawings in which:

Figure 1 shows a side elevational view of a plating line which may embody the present invention.

2,723,953 Patented Nov. 15, 1955 Figure 2 shows a sectional view taken substantially along the line 22 of Figure 1.

Figure 3 shows one form of electrical circuit for selectively disconnecting plating anodes.

Figure 4 shows an alternative circuit for disconnecting plating anodes.

I Figure 5 shows a somewhat more complex circuit for disconnecting plating anodes.

Referring now to Figures 1 and 2, a strip S to be plated is guided over a plurality of upper rollers 10 and lower rollers (not shown) so that the strip alternately moves downwardly and then upwardly within a plating tank12. Within the tank and spaced at substantially equal distances from the path of strip S are a plurality of plating anodes 14. As is clearly shown in Figure 1, alternate anodes alongthe tank will serve to plate opposite sides of the strip S. That is, those of anodes '14 positioned directly beneath upper rollers 10 will be exposed through the electrolytic bath to the undersurface of strip 10 and the alternate anodes will be exposed to the upper surface of the strip. 7

Each of the anodes 14 is connected through a flexible strap 16 to one terminal of a heavy-duty electrical contactor 18. The oher terminal of contactor 18 is then connected through a strap 20 to a bus bar 22.

For convenience in describing the invention, each of the contactors as shown in Figure 1 has been designated with a reference numeral, beginning with 1 at the lefthand side of the view in Figure 1.

From the foregoing, it will be apparent that the anodes connected with a contactor designated by the odd numbers, 1, 3, etc. will plate the upper surface of the strip S and the even numbered contactors 2, 4, etc. will supply current for plating the underside of the strip.

Referring now to Figure 3, a suitable control circuit according to the present invention will be described. In this figure, the control coils of contactors 18 are diagrammatically shown and here designated 'as 18'. Figure 3 shows one group of contactors arranged for simultaneous operation. This group may comprise a certain combination of either even numbered or odd numbered contactors. For example, as designated by the numerals on each of the diagrammatic contactor coils 18, the circuit in Figure 3 may control contactors 1, 5, 9, 13, 17, and 21. Each of the coils 18' is connected between a first side 24 and a second side 26 of an electric supply line. A pushbutton start switch 28 is provided for completing a circuit through a master relay coil 30. When switch 28 is operated, current will flow through coil 30 and will close circuits through relay arms 30 and 30". The circuit through arm 30 will complete a holding circuit through a normally closed pushbutton stop switch 32. The circuit through relay arm 30" will simultaneously energize all of the illustrated contactor coils 18' and circuits will be completed from bus bar 22 through the contacts of each contactor 18 to each of the designated anodes.

It will be understood from the above description of Figure 3 that a plurality of similar control circuits may be arranged between supply lines 24 and 26 for providing overall control of each of the anodes 14 associated with the complete plating operations. For example, a second control circuit may operate the remaining odd numbered contactors 3, 7, 11, etc. and the third and fourth control circuits may operate the even numbered contactors in two groups. By use of this modification of the invention, ratio plating could be obtained in which both sides of the strip could receive a full deposit or one or both sides could receive a deposit of 50% by weight since the anodes operating on either side of the strip S are arranged in two groups. The operating group may be interchanged at 3 preselected times to prevent destruction of any particular group of anodes.

It will furthermore be appreciated that each anode may be controlled independently of the others. That is, a switchboard may be established at a convenient location and arrangement made for grouping control switches as desired, as by rotary switches and the like to actuate any given combination of anodes.

It will furthermore be understood that each contactor 18 may be provided with interlocking contacts for supplying current to an indicator lamp at the switchboard Whenever the particular contactor is closed.

Figure 4 shows a circuit similar to that shown in Figure 3 except that operation is simply under the control of a single-pole, single-throw switch 32, which completes a circuit through master relay 34.

In Figure 5, there is illustrated a further extension of the grouping circuits described above in connection with Figures 3 and 4. In this modification, operation of start switch 36 will establish a holding circuit through stop switch 38 and through relay arm 40" will complete circuits through a plurality of master relay coils 42. Each of the relay coils will operate a relay arm 42'. This is indicated in Figure 5 by the dash line extending between coil 42 and the same coil shown in phantom line immediately above relay arm 42'. When arm 42 is operated, a further circuit will be completed through the coils 44 of two auxiliary relays. The auxiliary relay coils 44 will in turn operate a group of relay arms 44' associated therewith, as indicated by the dash line extending from coils 44 in Figure 5. Whenever the groups of relay lines 44' are operated, current will flow through contactor coils 18', if individual selector switches 46 associated with each relay coil 18 are closed. It will be clear from Figure 5 how the selector switches 46 may be pre-set to generally establish the anodes into operating groups and operation of start switches such as switch 36 may energize certain of the anode groups.

In any given embodiment of the invention, the on-off time interval of operation of the various anode groups can be controlled either manually or automatically. That is, an operator may supervise a centrally located switchboard and manipulate the control switches at predetermined intervals. On the contrary, the various control switches may be connected with any suitable motor-driven switch such as a rotary drum selector switch and proper control of the anodes will come about automatically.

It will be understood that the foregoing detailed description has been given only for purposes of illustration and the scope of the invention is to be determined from I the appended claims.

What is claimed is:

1. In electrolytic plating apparatus, a plating tank, a plurality of plating anodes positioned in said tank, means for guiding a strip to be plated in juxtaposition to the anodes and for moving the strip at a predetermined constant rate of speed, a plurality of said plating anodes being positioned to plate on one side of the strip and arranged in at least one group and a second plurality of anodes including at least one group being positioned to plate on the opposite side of the strip, means for electrically connecting the anodes of the groups to a source of electric current, said connecting means comprising electrically controlled switch means for each of the anodes, control circuits including relays for actuating the switch means for predetermined groups of anodes and a master switch means for energizing said relays.

2. In electrolytic plating apparatus, a plating tank, a plurality of plating anodes positioned in said tank, means for guiding a strip to be plated in juxtaposition to the anodes and for moving the strip at a predetermined constant rate of speed, a plurality of said plating anodes being positioned to plate on one side of the strip and arranged in at least one group, and a second plurality of anodes including at least one group being positioned to plate on the opposite side of the strip, means for electrically connecting the anodes of the groups to a source of electric current, said connecting means comprising electrically controlled switch means for each of the anodes, a plurality of control circuits each including an auxiliary relay for actuating the switch means of predetermined groups of anodes, a master control circuit including a master relay for controlling selected auxiliary relays and a master switch means for energizing the master relay.

3. Apparatus as in claim 2 wherein each of said switch means is further provided with a selector switch electrically connected between each said switch means and said auxiliary relays for selectively excluding predetermined switch means from operation.

4. Apparatus as in claim 2 wherein an electrical holding circuit is completed upon energization of said master relay.

5. Apparatus as in claim 2 including means to automatically operate the switch means of the anode groups at predetermined time intervals.

References Cited in the file of this patent UNITED STATES PATENTS 902,892 Lutz Nov. 3, 1908 998,379 Namekawa July 18, 1911 1,412,909 Voigt Apr. 18, 1922 2,479,317 Cook Aug. 16, 1949 FOREIGN PATENTS 558,130 Great Britain Dec. 22, 1943 rip-m 

1. IN ELECTROLYTIC PLATING APPARATUS, A PLATING TANK, A PLURALITY OF PLATING ANODES POSITIONED IN SAID TANK, MEANS FOR GUIDING A STRIP TO BE PLATED IN JUXTAPOSITION TO THE ANODES AND FOR MOVING THE STRIP AT A PREDETERMINED CONSTANT RATE OF SPEED, A PLURALITY OF SAID PLATING ANODES BEING POSITIONED TO PLATE ON ONE SIDE OF THE STRIP AND ARRANGED IN AT LEAST ONE GROUP AND A SECOND PLURALITY OF ANODES INCLUDING AT LEAST ONE GROUP BEING POSITIONED TO PLATE ON THE OPPOSITE SIDE OF THE STRIP, MEANS FOR ELECTRICALLY CONNECTING THE ANODES OF THE GROUPS TO A SOURCE OF ELECTRIC CURRENT, SAID CONNECTING MEANS COMPRISING ELECTRICALLY CONTROLLED SWITCH MEANS FOR EACH OF THE ANODES, CONTROL CIRCUITS INCLUDING RELAYS FOR ACTUATING THE SWITCH MEANS FOR PREDETERMINED GROUPS OF ANODES AND A MASTER SWITCH MEANS FOR ENERGIZING SAID RELAYS. 